Hypothermia is frequently observed in anorexia nervosa (AN) but is often overlooked clinically. External heat application has been proposed as a supportive adjunct. We conducted a retrospective study to determine the frequency of hypothermia in a highly selected inpatient population with AN admitted to a specialized medical (somatic) unit because of low BMI and/or somatic complications, and to explore clinical correlates and implications. In this naturalistic clinical setting, we retrospectively reviewed routinely collected clinical and biochemical data from admissions. Hypothermia was defined as tympanic temperature < 35.8°C. Clinical and biochemical variables were compared between normothermic and hypothermic patients, and multivariable logistic regression was used to identify factors associated with hypothermia. Among 111 patients, 10.8% had tympanic temperature < 35.8°C. During short-term hospitalization with supported meals, fluid and electrolyte correction, and partial weight restoration, most hypothermic patients achieved normothermia. However, persistent hypothermia may represent an underrecognized treatment target; future studies should assess its impact on outcomes and evaluate whether adjunctive warming interventions improve recovery.